- At the time of registration: Patients must have recovered from the toxic effects of prior therapy: greater than or equal to 28 days from any investigational agent, greater than or equal to 28 days from prior cytotoxic therapy, greater than or equal to 14 days from vincristine, greater than or equal to 42 days from nitrosoureas, greater than or equal to 21 days from procarbazine administration, >21 days from bevacizumab administration and greater than or equal to 7 days for non-cytotoxic agents, e.g., interferon, tamoxifen, thalidomide, cis-retinoic acid, etc. (radiosensitizer does not count). Any questions related to the definition of noncytotoxic agents should be directed to Academic PI.